Nowadays, with the improvement of the running speed and transport efficiency of trains, if a train occurs derailment, circumstances such like line close, train shutting down or delay will be caused. Therefore, the requirement for the anti-derailment performance of bogies is higher and higher, especially to the main line railway where the transportation is relatively busy.
The bogie without fixing an anti-derailment apparatus relies only on the flange of the wheel itself for taking precautions against the anti-derailment of the bogie. Since the constrained points are relatively fewer, the anti-derailment capability is relative weak.
The Chinese patent application with the publication No. CN204548142U discloses a rail vehicle and safety protection apparatus for anti-derailment. The basic principle of the apparatus is to allow the safety protection apparatus to contact with the outside of the rail after the wheelset is separated from the steel rail, so as to avoid the whole bogie separating from the railway line. The safety protection apparatus allows the wheelset to be separated from the rail, and then avoids the lateral movement of the vehicle being too much by use of the apparatus. The function of the apparatus works only after the vehicle occurs derailment. The bogie without fixing the above safety protection apparatus cannot effectively limit derailment accidents such as rail climbing, and after the wheelset is separated from the rail, the lateral vibration of the vehicle is relatively large.